#4017: fix for function expanding

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@31525 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Disabled prev/next buttons in BrowseGUI are now hidden.
Bugfix: Too many displayed materials (last image was positioned behind the prev image)

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@31526 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
Refactor monotone to triangles

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@31527 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e
defined = true by default

git-svn-id: http://dev.geogebra.org/svn/trunk/geogebra@31528 23ce0884-8a58-47d3-bc5c-ddf1cd5b9f9e